Broken rings

[john.t5]

This is the piston out of my son's GP200 motor. It lost power on the way to a rally but made it there and back slowly. He was flat out for about 45 miles on motorway before it happened. Set up is a stage 4 200 with a Taffy copy and a 28mm Delly. can't see any obvious reason for it happening but maybe some of the experts will be able to tell more from the photos. Barrel is barely marked.

[DaveTomo]

This is the piston out of my son's GP200 motor. It lost power on the way to a rally but made it there and back slowly. He was flat out for about 45 miles on motorway before it happened

and maybe added to this http://www.lambrettaspares.com/info/mb- ... s+116.html (go about halfway down to the 3 ring piston picture)